The performance of a micro electro mechanical system is closely related to the material parameter. Due to the effect in processing, some material parameters change, and these uncertain factors caused by the processing technique resulted in uncertainty and instability of the device design and performance prediction. The material parameter testing is aimed to real-time measure the material parameter of the micro electro mechanical device manufactured by a specific process, monitor stability of the process and feed the parameter back to the designer in order to modify the design. Therefore, testing using general equipment without leaving the processing environment becomes a necessary measure for process monitoring. The physical parameters of the material mechanical properties mainly include residual stress, Young's modulus, Poisson's ratio, and the breaking strength, etc.
The film material is widely used in the micro electro mechanical device structure, especially in the surface micromachining structure, and the film material is the primary material of the structural materials. Currently, most online testing structures for material parameter are directed to conductive materials, such as doped monocrystalline silicon, doped polycrystalline silicon and metals, etc. For the insulating materials, such as silicon nitride, silicon dioxide and silicon dioxide-wrapped monocrystalline silicon or polycrystalline silicon, it is not easy to realize direct loading and electrical detection of the testing signal due to insulating properties of these materials.